Alpine Installation, Operating, and Service Instructions

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Tekmar 265 Based Control System (or equal)
Sequence of Operation
The Tekmar 265 Control (or equal) can control up to three (3) boilers and an Indirect Water Heater. When a call for heat is received by the Tekmar 265 Control, the control will fire either one or more boilers in either parallel or sequential firing mode to establish a required reset water temperature in the system supply main based on outdoor temperature. The boilers will modulate based on an Analog communication signal established between the Tekmar 265 Control and each boiler’s Sage2.X Control. The boiler(s) and system supply water temperature will be reset together to maintain the input that is needed to the system. When a call for Indirect Hot Water is generated to the Tekmar 265, the control will de-energize the zone pump control (ZC terminal), energize the Indirect pump and modulate the boiler firing to establish a setpoint temperature in the main for the Indirect Heater using Priority. The Tekmar 265 also controls each boiler’s pump and a post purge of leftover temperature in the boilers will occur at the end of the call for Indirect Hot Water.
Figure 31A: Multiple Boiler Wiring Diagram w/Tekmar 265 Control
VIII. Electrical (continued)